Conventional mirrors are designed to reflect ambient light at all times. While this may be desirable in the daytime, trailing vehicles can often blind the driver at night by not having their headlights dimmed and shining the headlights into the mirrors of the driver's vehicle. One approach to address this is to provide two reflective surfaces with different reflectivity characteristics and provide a mechanical adjustment on the mirror to allow for day and nighttime driving. Another approach uses a wedge shaped mirror such that maximum reflectivity (e.g., in a day mode) is accomplished when the image is reflected off the rear portion of the mirror which has the reflective coating. When an alternative mode is desired, such as a night mode, the mirror is adjusted such that the reflected light is reflected off the front glass which has a lower reflectivity than the rear portion.
Other approaches employ interior vehicle mirrors that operate electrochromatically such that they dim reflected light from trailing vehicles. The mirrors are calibrated to react to an amount of ambient light as read by light sensors and are able to adjust the level of reflectivity to reduce the chances of a driver from being blinded by trailing vehicles at night.
For certain vehicles, such as military combat vehicles, it is desirable to provide total non-reflectivity of the mirror during specific times, such as during particular combat operations. For instance, covert and special operations missions are often executed at night and the ability to perform such missions without being observed by enemy forces is key. To prevent any reflectivity off the mirrors during such combat missions, the mirrors are often either removed entirely or moved to a position that masks their reflective surface from observation. For some situations, duct tape may also be placed over the mirrors to prevent light from reflecting. The ability to eliminate the observability of the mirror resulting from light reflection may also be desirable for vehicles used for security purposes. Security vehicles may be vehicles used for special operations purposes, police operations, or private security purposes. The conventional approaches that have been used to prevent light reflection off a vehicle mirror defeat the purpose of having a vehicle mirror and require the time and effort of military or security personnel to move or remove (and then re-install) the mirrors as needed.
Accordingly, there is a need for improved light blocking devices for vehicle mirrors that are adapted to selectively block the reflectivity of ambient light from the mirrors in a convenient manner.